This study was designed to investigate persistence of gentamicin residues in milk after the intramammary treatment of lactating cows for mastitis. Milk samples were collected at a 1-d interval after the last administr...This study was designed to investigate persistence of gentamicin residues in milk after the intramammary treatment of lactating cows for mastitis. Milk samples were collected at a 1-d interval after the last administration from 34 individual cows that had received intramammary infusions of gentamicin. The doses and treatment times evaluated in this study represented those that have been applied by veterinarians in practice. The tetrazolium chloride assay was used to determine whether there were significant residues of the antibiotic in the samples. Persistence of detectable drug residues in milk from 33 cows (28 cows, ≤6 infusions at ≤0.7 g gentamicin; and 5 cows, 2 infusions at 0.8 g gentamicin) did not exceed 5 d; but 1 cow (5 infusions at 0.8 g gentamicin) had detectable residues in its milk for 9 d. Our results suggest that a 5-d milk withdrawal period might be insufficient to secure the clearance of the contamination of gentamicin, because treatment times and dosages contribute to the antibiotic clearance. A larger scale of samples are needed for further investigations.展开更多
The purpose of this study was to investigate the residue elimination of ceftiofur hydrochloride in milk of postpartum cows after intramammary infusing at dry-off. An ultra-high performance liquid chromatography-tandem...The purpose of this study was to investigate the residue elimination of ceftiofur hydrochloride in milk of postpartum cows after intramammary infusing at dry-off. An ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/ MS） method was developed and validated to detect ceftiofur hydrochloride residue in milk. Through preprocessing, ceftiofur hydrochloride was derivatized into a more stable compound dedfuroyl ceftiofur acetamide （DCA） for further analysis. The linear range of DCA was 0.1 to 50 μg kg-1. Average recoveries of DCA were 82.52-105.86％. The intra-day and interday coefficients of variation （CV） were 2.95-9.82 and 6.41-7.43％, respectively. The limit of detection （LOD） and limit of quantitation （LOQ） scores were 0.05 and 0.1 μg kg-1, respectively. These parameters showed this method was reliable and valid. Twelve cows were administrated 10 mL ceftiofur hydrochloride by intramammary infusion （corresponding to 500 mg ceftiofur） to each udder after the last milking before the dry-off period. Milk was collected from each udder of cow at 12, 24, 36, 48, 60 and 72 h after calving and was mixed for each time point and each cow, then subjected to UPLC-MS/MS analysis. The results showed, the DCA concentrations in all milk samples were less than LOQ and the maximum residue limit （MRL） 100 μg kg-1, which suggested the withdrawal time of ceftiofur hydrochloride intramammary infusion used for preventing and curing mastitis in dry cows was 0 day. The study provided guidance for the clinical applications of ceftiofur hydrochloride intramammary infusion （dry cow）.展开更多
Transient E. coli intramammary infections (IMI) are usually associated with rapid onset of clinical signs including mammary gland swelling and abnormal milk with rapid clearance of bacteria from milk. Conversely, repo...Transient E. coli intramammary infections (IMI) are usually associated with rapid onset of clinical signs including mammary gland swelling and abnormal milk with rapid clearance of bacteria from milk. Conversely, reports have described strains of E. coli showing very different clinical trends. Persistent E. coli IMI are associated with mild clinical symptoms that disappear shortly after the onset of infection, possibly flaring-up intermittently during lactation. In the present study, we evaluated a strain of E. coli isolated from a cow with persistent mastitis to determine if the experimental infection model mimics naturally occurring persistent E. coli IMI. Uninfected mammary quarters of 7 Holstein heifers were infused within 10 days of calving with 50 colony-forming units of a persistent E. coli strain. Six of 7 heifers developed mild clinical mastitis with elevated rectal temperatures within 9 to 36 h after infusion. The challenge strain was isolated intermittently in milk from all infected mammary quarters during the first two weeks after infusion and 3 animals continued to shed E. coli periodically during the sampling period. One animal shed E. coli intermittently in milk for 172 d after challenge and developed clinical mastitis four times during this period. The isolated strain had an identical pulsed-field gel electrophoresis profile as the E. coli strain used to infuse mammary glands. The experimental IMI model described here mimics very closely naturally occurring persistent E. coli IMI, thus providing an excellent in vivo model to better understand pathogenesis and to facilitate development of control strategies for this important mastitis pathogen.展开更多
Background Bovine mastitis is one of the main causes of reduced production in dairy cows.The infection of the mammary gland is mainly caused by the bacterium Staphylococcus aureus,whose resistant strains make the trea...Background Bovine mastitis is one of the main causes of reduced production in dairy cows.The infection of the mammary gland is mainly caused by the bacterium Staphylococcus aureus,whose resistant strains make the treatment of mastitis with conventional antibiotics very difficult and result in high losses.Therefore,it is impor-tant to develop novel therapeutic agents to overcome the resistance of mastitis-causing strains.In this study,novel selenium-tellurium based nanoparticles(SeTeNPs)were synthesized and characterized.Their antibacterial activity and biocompatibility were evaluated both in vitro and in vivo using a bovine model.A total of 10 heifers were divided into experimental and control groups(5 animals each).After intramammary infection with methicillin resistant S.aureus(MRSA)and the development of clinical signs of mastitis,a dose of SeTeNPs was administered to all quarters in the experimental group.Results Based on in vitro tests,the concentration of 149.70 mg/L and 263.95 mg/L of Se and Te,respectively,was used for application into the mammary gland.Three days after SeTeNPs administration,MRSA counts in the experimental group showed a significant reduction(P<0.01)compared to the control group.The inhibitory effect observed within the in vitro experiments was thus confirmed,resulting in the suppression of infection in ani-mals.Moreover,the superior biocompatibility of SeTeNPs in the organism was demonstrated,as the nanoparticles did not significantly alter the inflammatory response or histopathology at the site of application,i.e.,mammary gland,compared to the control group(P>0.05).Additionally,the metabolic profile of the blood plasma as well as the histology of the main organs remained unaffected,indicating that the nanoparticles had no adverse effects on the organism.Conclusions Our findings suggest that SeTeNPs can be used as a promising treatment for bovine mastitis in the pres-ence of resistant bacteria.However,the current study is limited by its small sample size,making it primarily a proof of the concept for the efficacy of intramammary-applied SeTeNPs.Therefore,further research with a larger sample size is needed to validate these results.展开更多
Undoubtedly, since its appearance, the interest and use of autologous fat transfer (AFT) as a breast reconstruction technique have been increasing, becoming one of the main surgical alternatives for aesthetic breast a...Undoubtedly, since its appearance, the interest and use of autologous fat transfer (AFT) as a breast reconstruction technique have been increasing, becoming one of the main surgical alternatives for aesthetic breast augmentation. This increase in its popularity has led to the development of new technologies to increase its efficacy and safety, however, it has inherently implied the inadequate use of this procedure, mainly when performed by unqualified medical personnel. We present the case of a patient with complications following a breast AFT for aesthetic purposes, performed by a general practitioner without a specialty in plastic and reconstructive surgery.展开更多
The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining th...The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining the first 2 milk recording results after calving). Another aim was to evaluate the milk urea (MU) content as a potential supplementary indicator to SCC or CSCC for the identification of IMI in primiparous cows after calving. This retrospective observational study was conducted on records of test-day of primiparous cows over a period of 6 years (January 2016 to December 2021. The SCC data for 158 Holstein Friesian primiparous cows, with their first milk recording 5 to 35 days after calving and their second milk recording 28 to 56 days in milk (DIM), were identified. Each primiparous cow was assigned a CSCC category (low-low, low-high, high-low or high-high) based on the CSCC at the first 2 milking recordings using the following cut-offs: ≤150,000 cells/ml (low), >150,000 cells/ml (high). The association between CSCC categories and MV content was analyzed using correlation models. At the first milk recording, a proportion of 63.29% was in the low SCC category, and the rest (36.71%) was in the high SCC category. At the second milk recording, a proportion of primiparous cows in CSCC categories was 59.49%, 3.80%, 27.85% and 8.86% in low-low, low-high, high-low and high-high, respectively. At the second milk recording, a proportion of 12.66% of primiparous cows was in the high CSCC category and a proportion of 87.34% of primiparous cows was in the low CSCC category, indicating a poor and a good udder health, respectively. The association of SCC with MU content in low and in high SCC categories at the first milk recording was positive and moderate (+0.49) and negative and strong (-0.97), respectively. The association of CSCC categories with MU contents at the second milk recording was inconclusive. We concluded that CSCC categories may be a useful tool for identifying success and problems regarding the udder health of primiparous cows in early lactation.展开更多
基金supported by the Science and Technology Department of Zhejiang Province (Nos. 2005C12015 and 2007C32025)the Education Department of Zhejiang Province (No. 20061319), China
文摘This study was designed to investigate persistence of gentamicin residues in milk after the intramammary treatment of lactating cows for mastitis. Milk samples were collected at a 1-d interval after the last administration from 34 individual cows that had received intramammary infusions of gentamicin. The doses and treatment times evaluated in this study represented those that have been applied by veterinarians in practice. The tetrazolium chloride assay was used to determine whether there were significant residues of the antibiotic in the samples. Persistence of detectable drug residues in milk from 33 cows (28 cows, ≤6 infusions at ≤0.7 g gentamicin; and 5 cows, 2 infusions at 0.8 g gentamicin) did not exceed 5 d; but 1 cow (5 infusions at 0.8 g gentamicin) had detectable residues in its milk for 9 d. Our results suggest that a 5-d milk withdrawal period might be insufficient to secure the clearance of the contamination of gentamicin, because treatment times and dosages contribute to the antibiotic clearance. A larger scale of samples are needed for further investigations.
基金supported by the Beijing Diary Industry Innovation Team,Chinathe Special Fund of the Chinese Academy of Agricultural Sciences Innovation Project (CAAS-FRI-06)
文摘The purpose of this study was to investigate the residue elimination of ceftiofur hydrochloride in milk of postpartum cows after intramammary infusing at dry-off. An ultra-high performance liquid chromatography-tandem mass spectrometry （UPLC-MS/ MS） method was developed and validated to detect ceftiofur hydrochloride residue in milk. Through preprocessing, ceftiofur hydrochloride was derivatized into a more stable compound dedfuroyl ceftiofur acetamide （DCA） for further analysis. The linear range of DCA was 0.1 to 50 μg kg-1. Average recoveries of DCA were 82.52-105.86％. The intra-day and interday coefficients of variation （CV） were 2.95-9.82 and 6.41-7.43％, respectively. The limit of detection （LOD） and limit of quantitation （LOQ） scores were 0.05 and 0.1 μg kg-1, respectively. These parameters showed this method was reliable and valid. Twelve cows were administrated 10 mL ceftiofur hydrochloride by intramammary infusion （corresponding to 500 mg ceftiofur） to each udder after the last milking before the dry-off period. Milk was collected from each udder of cow at 12, 24, 36, 48, 60 and 72 h after calving and was mixed for each time point and each cow, then subjected to UPLC-MS/MS analysis. The results showed, the DCA concentrations in all milk samples were less than LOQ and the maximum residue limit （MRL） 100 μg kg-1, which suggested the withdrawal time of ceftiofur hydrochloride intramammary infusion used for preventing and curing mastitis in dry cows was 0 day. The study provided guidance for the clinical applications of ceftiofur hydrochloride intramammary infusion （dry cow）.
文摘Transient E. coli intramammary infections (IMI) are usually associated with rapid onset of clinical signs including mammary gland swelling and abnormal milk with rapid clearance of bacteria from milk. Conversely, reports have described strains of E. coli showing very different clinical trends. Persistent E. coli IMI are associated with mild clinical symptoms that disappear shortly after the onset of infection, possibly flaring-up intermittently during lactation. In the present study, we evaluated a strain of E. coli isolated from a cow with persistent mastitis to determine if the experimental infection model mimics naturally occurring persistent E. coli IMI. Uninfected mammary quarters of 7 Holstein heifers were infused within 10 days of calving with 50 colony-forming units of a persistent E. coli strain. Six of 7 heifers developed mild clinical mastitis with elevated rectal temperatures within 9 to 36 h after infusion. The challenge strain was isolated intermittently in milk from all infected mammary quarters during the first two weeks after infusion and 3 animals continued to shed E. coli periodically during the sampling period. One animal shed E. coli intermittently in milk for 172 d after challenge and developed clinical mastitis four times during this period. The isolated strain had an identical pulsed-field gel electrophoresis profile as the E. coli strain used to infuse mammary glands. The experimental IMI model described here mimics very closely naturally occurring persistent E. coli IMI, thus providing an excellent in vivo model to better understand pathogenesis and to facilitate development of control strategies for this important mastitis pathogen.
基金Financial support from ERDF “Multidisciplinary research to increase application potential of nanomaterials in agricultural practice” (No.CZ.02.1.01/0.0/0.0/16_025/0007314)the assistance provided by the Research Infrastructure Nano Envi Cz, supported by the Ministry of Education, Youth and Sports of the Czech Republic under Project No. LM2018124+4 种基金Czech Nano Lab Research Infrastructure supported by MEYS CR (LM2023051)Grant Agency of Gregor Johann Mendel (C-MNG-23–002)further supported by the Ministry of Agriculture of the Czech Republic by Grant RO0523Internal Grant Agency of University of Veterinary Sciences Brno (223/2024/FVHE)the National Institute of Virology and Bacteriology project (Programme EXCELES, Project ID No. LX22NPO5103)-Funded by the European Union-Next Generation EU.
文摘Background Bovine mastitis is one of the main causes of reduced production in dairy cows.The infection of the mammary gland is mainly caused by the bacterium Staphylococcus aureus,whose resistant strains make the treatment of mastitis with conventional antibiotics very difficult and result in high losses.Therefore,it is impor-tant to develop novel therapeutic agents to overcome the resistance of mastitis-causing strains.In this study,novel selenium-tellurium based nanoparticles(SeTeNPs)were synthesized and characterized.Their antibacterial activity and biocompatibility were evaluated both in vitro and in vivo using a bovine model.A total of 10 heifers were divided into experimental and control groups(5 animals each).After intramammary infection with methicillin resistant S.aureus(MRSA)and the development of clinical signs of mastitis,a dose of SeTeNPs was administered to all quarters in the experimental group.Results Based on in vitro tests,the concentration of 149.70 mg/L and 263.95 mg/L of Se and Te,respectively,was used for application into the mammary gland.Three days after SeTeNPs administration,MRSA counts in the experimental group showed a significant reduction(P<0.01)compared to the control group.The inhibitory effect observed within the in vitro experiments was thus confirmed,resulting in the suppression of infection in ani-mals.Moreover,the superior biocompatibility of SeTeNPs in the organism was demonstrated,as the nanoparticles did not significantly alter the inflammatory response or histopathology at the site of application,i.e.,mammary gland,compared to the control group(P>0.05).Additionally,the metabolic profile of the blood plasma as well as the histology of the main organs remained unaffected,indicating that the nanoparticles had no adverse effects on the organism.Conclusions Our findings suggest that SeTeNPs can be used as a promising treatment for bovine mastitis in the pres-ence of resistant bacteria.However,the current study is limited by its small sample size,making it primarily a proof of the concept for the efficacy of intramammary-applied SeTeNPs.Therefore,further research with a larger sample size is needed to validate these results.
文摘Undoubtedly, since its appearance, the interest and use of autologous fat transfer (AFT) as a breast reconstruction technique have been increasing, becoming one of the main surgical alternatives for aesthetic breast augmentation. This increase in its popularity has led to the development of new technologies to increase its efficacy and safety, however, it has inherently implied the inadequate use of this procedure, mainly when performed by unqualified medical personnel. We present the case of a patient with complications following a breast AFT for aesthetic purposes, performed by a general practitioner without a specialty in plastic and reconstructive surgery.
文摘The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining the first 2 milk recording results after calving). Another aim was to evaluate the milk urea (MU) content as a potential supplementary indicator to SCC or CSCC for the identification of IMI in primiparous cows after calving. This retrospective observational study was conducted on records of test-day of primiparous cows over a period of 6 years (January 2016 to December 2021. The SCC data for 158 Holstein Friesian primiparous cows, with their first milk recording 5 to 35 days after calving and their second milk recording 28 to 56 days in milk (DIM), were identified. Each primiparous cow was assigned a CSCC category (low-low, low-high, high-low or high-high) based on the CSCC at the first 2 milking recordings using the following cut-offs: ≤150,000 cells/ml (low), >150,000 cells/ml (high). The association between CSCC categories and MV content was analyzed using correlation models. At the first milk recording, a proportion of 63.29% was in the low SCC category, and the rest (36.71%) was in the high SCC category. At the second milk recording, a proportion of primiparous cows in CSCC categories was 59.49%, 3.80%, 27.85% and 8.86% in low-low, low-high, high-low and high-high, respectively. At the second milk recording, a proportion of 12.66% of primiparous cows was in the high CSCC category and a proportion of 87.34% of primiparous cows was in the low CSCC category, indicating a poor and a good udder health, respectively. The association of SCC with MU content in low and in high SCC categories at the first milk recording was positive and moderate (+0.49) and negative and strong (-0.97), respectively. The association of CSCC categories with MU contents at the second milk recording was inconclusive. We concluded that CSCC categories may be a useful tool for identifying success and problems regarding the udder health of primiparous cows in early lactation.
